fs: bump inode and dentry counters to long
This series reworks our current object cache shrinking infrastructure in
two main ways:
* Noticing that a lot of users copy and paste their own version of LRU
lists for objects, we put some effort in providing a generic version.
It is modeled after the filesystem users: dentries, inodes, and xfs
(for various tasks), but we expect that other users could benefit in
the near future with little or no modification. Let us know if you
have any issues.
* The underlying list_lru being proposed automatically and
transparently keeps the elements in per-node lists, and is able to
manipulate the node lists individually. Given this infrastructure, we
are able to modify the up-to-now hammer called shrink_slab to proceed
with node-reclaim instead of always searching memory from all over like
it has been doing.
Per-node lru lists are also expected to lead to less contention in the lru
locks on multi-node scans, since we are now no longer fighting for a
global lock. The locks usually disappear from the profilers with this
change.
Although we have no official benchmarks for this version - be our guest to
independently evaluate this - earlier versions of this series were
performance tested (details at
http://permalink.gmane.org/gmane.linux.kernel.mm/100537) yielding no
visible performance regressions while yielding a better qualitative
behavior in NUMA machines.
With this infrastructure in place, we can use the list_lru entry point to
provide memcg isolation and per-memcg targeted reclaim. Historically,
those two pieces of work have been posted together. This version presents
only the infrastructure work, deferring the memcg work for a later time,
so we can focus on getting this part tested. You can see more about the
history of such work at http://lwn.net/Articles/552769/
Dave Chinner (18):
dcache: convert dentry_stat.nr_unused to per-cpu counters
dentry: move to per-sb LRU locks
dcache: remove dentries from LRU before putting on dispose list
mm: new shrinker API
shrinker: convert superblock shrinkers to new API
list: add a new LRU list type
inode: convert inode lru list to generic lru list code.
dcache: convert to use new lru list infrastructure
list_lru: per-node list infrastructure
shrinker: add node awareness
fs: convert inode and dentry shrinking to be node aware
xfs: convert buftarg LRU to generic code
xfs: rework buffer dispose list tracking
xfs: convert dquot cache lru to list_lru
fs: convert fs shrinkers to new scan/count API
drivers: convert shrinkers to new count/scan API
shrinker: convert remaining shrinkers to count/scan API
shrinker: Kill old ->shrink API.
Glauber Costa (7):
fs: bump inode and dentry counters to long
super: fix calculation of shrinkable objects for small numbers
list_lru: per-node API
vmscan: per-node deferred work
i915: bail out earlier when shrinker cannot acquire mutex
hugepage: convert huge zero page shrinker to new shrinker API
list_lru: dynamically adjust node arrays
This patch:
There are situations in very large machines in which we can have a large
quantity of dirty inodes, unused dentries, etc. This is particularly true
when umounting a filesystem, where eventually since every live object will
eventually be discarded.
Dave Chinner reported a problem with this while experimenting with the
shrinker revamp patchset. So we believe it is time for a change. This
patch just moves int to longs. Machines where it matters should have a
big long anyway.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index 4d9df3c..6ef1c2e 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -146,13 +146,13 @@
.age_limit = 45,
};
-static DEFINE_PER_CPU(unsigned int, nr_dentry);
+static DEFINE_PER_CPU(long, nr_dentry);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
-static int get_nr_dentry(void)
+static long get_nr_dentry(void)
{
int i;
- int sum = 0;
+ long sum = 0;
for_each_possible_cpu(i)
sum += per_cpu(nr_dentry, i);
return sum < 0 ? 0 : sum;
@@ -162,7 +162,7 @@
size_t *lenp, loff_t *ppos)
{
dentry_stat.nr_dentry = get_nr_dentry();
- return proc_dointvec(table, write, buffer, lenp, ppos);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
diff --git a/fs/inode.c b/fs/inode.c
index 93a0625..2a3c37e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -70,33 +70,33 @@
*/
struct inodes_stat_t inodes_stat;
-static DEFINE_PER_CPU(unsigned int, nr_inodes);
-static DEFINE_PER_CPU(unsigned int, nr_unused);
+static DEFINE_PER_CPU(unsigned long, nr_inodes);
+static DEFINE_PER_CPU(unsigned long, nr_unused);
static struct kmem_cache *inode_cachep __read_mostly;
-static int get_nr_inodes(void)
+static long get_nr_inodes(void)
{
int i;
- int sum = 0;
+ long sum = 0;
for_each_possible_cpu(i)
sum += per_cpu(nr_inodes, i);
return sum < 0 ? 0 : sum;
}
-static inline int get_nr_inodes_unused(void)
+static inline long get_nr_inodes_unused(void)
{
int i;
- int sum = 0;
+ long sum = 0;
for_each_possible_cpu(i)
sum += per_cpu(nr_unused, i);
return sum < 0 ? 0 : sum;
}
-int get_nr_dirty_inodes(void)
+long get_nr_dirty_inodes(void)
{
/* not actually dirty inodes, but a wild approximation */
- int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
+ long nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
return nr_dirty > 0 ? nr_dirty : 0;
}
@@ -109,7 +109,7 @@
{
inodes_stat.nr_inodes = get_nr_inodes();
inodes_stat.nr_unused = get_nr_inodes_unused();
- return proc_dointvec(table, write, buffer, lenp, ppos);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
diff --git a/fs/internal.h b/fs/internal.h
index 2be46ea..b649565 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -121,7 +121,7 @@
*/
extern void inode_wb_list_del(struct inode *inode);
-extern int get_nr_dirty_inodes(void);
+extern long get_nr_dirty_inodes(void);
extern void evict_inodes(struct super_block *);
extern int invalidate_inodes(struct super_block *, bool);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index feaa8d8..844a1ef 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -55,11 +55,11 @@
#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
struct dentry_stat_t {
- int nr_dentry;
- int nr_unused;
- int age_limit; /* age in seconds */
- int want_pages; /* pages requested by system */
- int dummy[2];
+ long nr_dentry;
+ long nr_unused;
+ long age_limit; /* age in seconds */
+ long want_pages; /* pages requested by system */
+ long dummy[2];
};
extern struct dentry_stat_t dentry_stat;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 49e71b0..3b3edac 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1271,12 +1271,12 @@
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
/* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
+ long s_nr_dentry_unused; /* # of dentry on lru */
/* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ long s_nr_inodes_unused; /* # of inodes on lru */
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index a4ed56c..6c28b61 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -49,9 +49,9 @@
};
struct inodes_stat_t {
- int nr_inodes;
- int nr_unused;
- int dummy[5]; /* padding for sysctl ABI compatibility */
+ long nr_inodes;
+ long nr_unused;
+ long dummy[5]; /* padding for sysctl ABI compatibility */
};
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 07f6fc4..7822cd8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1471,14 +1471,14 @@
{
.procname = "inode-nr",
.data = &inodes_stat,
- .maxlen = 2*sizeof(int),
+ .maxlen = 2*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_inodes,
},
{
.procname = "inode-state",
.data = &inodes_stat,
- .maxlen = 7*sizeof(int),
+ .maxlen = 7*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_inodes,
},
@@ -1508,7 +1508,7 @@
{
.procname = "dentry-state",
.data = &dentry_stat,
- .maxlen = 6*sizeof(int),
+ .maxlen = 6*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_dentry,
},